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league averages of TS%, eFG% and assisted vs. unassisted shots

For whatever reason, bball-ref doesn't have league averages for advanced stats (I actually asked them about that and they said they'd consider doing it) so I took it upon the liberty to calculate it myself. Now, I used their league average page to estimate the totals based on games played during the different seasons so the figures aren't exact but I think they're at most off by .1% points, which is no big deal.

but I don't understand the purpose of averaging the TS% and eFG% of every player of every position in the league. It skews the numbers when you're trying to compare a TS%/eFG% of a certain player to the league average because centers will naturally have higher efficiency and FG% numbers than guards would, etc....

but I don't understand the purpose of averaging the TS% and eFG% of every player of every position in the league. It skews the numbers when you're trying to compare a TS%/eFG% of a certain player to the league average because centers will naturally have higher efficiency and FG% numbers than guards would, etc....

That seems to be a good point to keep in mind, but I don't think it necessarily eliminates the potential usefulness of these stats. It does, however, present a solid caveat about being careful how to use them, or perhaps also advice about how to improve their usefulness (eg. position specific averages).

That said, anyone who just threw out TS% to compare, say, Nash and Howard, would automatically get called out by anyone who understands what the stat measures. And there could be ways to use these numbers to drive a point home.

Say, for example, the fact that Tim Duncan had a 53.7 TS% in 2010-11, which is under the league average, let alone the average for centers (which we can safely assume should be even higher), certainly says something about the extent to which his offensive game has dropped off.

As a single season point of reference, the 2010-11 season average TS% was 54.2% by pSk's calculation. What hoopdata has, by position, is:

Season 54.2 (nice work, pats!)
C 55.8
PF 54.6
SF 54.4
SG 54.0
PG 53.3

So the total deviation (sorry if my math terms aren't precise, but I think you understand what I mean) is 2.5%, 1.6% on the upper side of the average, and 0.9% on the lower. Which actually is less deviation than I'd have expected.

Which in turn points to another potentially interesting statistical experiment: Which stats deviate the most greatly when broken down by position from league averages?

but I don't understand the purpose of averaging the TS% and eFG% of every player of every position in the league. It skews the numbers when you're trying to compare a TS%/eFG% of a certain player to the league average because centers will naturally have higher efficiency and FG% numbers than guards would, etc....

For 07 onwards, it obviously makes sense to use positional averages and the data you find at hoopdata. Unfortunately, pre-07, there's no one that I know of that even bothers to calculate league averages for TS%/eFG%/other advanced stats, let alone for position.

The only way I can think of to calculate positional numbers pre-07 would be to go through the basketball-ref play index for each individual year, look at the totals, sum it up and manually calculate it for EACH position. And even then, you'd only get guard/forward/center averages. And that is a LOT of work. You're adding up the totals and calculating it for 3 different positions for each year going back 60+ years. That's a lot isn't it?

Sadly, we'll just have to make do with what I posted. However, perhaps there is a way to estimate positional numbers based on a regression. This would take some thought and time though.

As long as you keep in mind the caveat you mentioned, then this can still be useful. For example, if you are trying to compare 2 Centers from different eras, you may be ok. I think it would be reasonable to assume the deviation in TS% for Centers hasn't changed much from league average (Centers will always have a higher TS% than average), other then the effects of the competition, which would be something you'd want to take into account anyways. The one area where it obviously gets really tricky is comparing guards before the 3 point line vs. guards after the 3 point line. Obviously guards who have the advantage of the 3 point line are naturally going to have higher TS%s. And since there's no positional data available for TS%/other advanced stats pre-07, that would be a tough comp.

Edit: Just thought of a way to approach that- Calculate league average 2 point % for the recent year and then use average 3 point % for that year to finish the TS% calculation. This should negate some of the effect, although a player who shoots the 3 well will still have an advantage.

So to explain using an example, say I'm comparing Bob Cousy in 57-58 to Chris Paul this year (he shot the 3 above average so that will help him in this comp).

The league average in 2 point % could be calculated as such:
(FGM-3PTM) / (FGA-3PTA)
You could do this for Paul last year, although there are sites that have 2 point % already calculated. You don't need to do this for Cousy since obvioiusly TS% in 57-58 is just based on 2 point shots anyways.

Add in FTs and you have TS% without 3 pointers. Do that for the league average too and you've essentially removed the 3 pointer from the equation. Then you get a more fair comparison (though still flawed) between league averages.

Personally, I find the Ast/FG stat more interesting (or assisted vs. unassisted). I could also post Ast/Shot attempts too, if anyone wants. There isn't much difference though. The same basic trends apply.

...and then those deviations were done for all seasons we have the data for, and then we averaged each position's deviation over those 5 or so seasons, we'd probably end up with a rough standard for what should be a fairly reasonably assumed deviation from league average by position in seasons predating 06-07.

Can I post these on my website? Can I see your methodology or the link to that BBR page.

Originally Posted by RZZZA

but I don't understand the purpose of averaging the TS% and eFG% of every player of every position in the league. It skews the numbers when you're trying to compare a TS%/eFG% of a certain player to the league average because centers will naturally have higher efficiency and FG% numbers than guards would, etc....

I dont think thats true, eFG% incorporates 3's and Bigs rarely shoot those, TS% is obviously about getting to the line. I dont see how the #'s are skewed in any way.

If I remember correctly, I calculated them by multiplying out each season by games played and then using the totals to calculate each stat. But I have the spreadsheet somewhere, let me look for it and see how I did it.

Does the idea in my post above about average deviation by position work out right, or is it flawed somehow? It makes sense to me, but the math with this stats stuff usually tends to go a few levels deeper than I'm capable of handling.